Various enclosures have been provided for drinking receptacles, particularly hot coffee or the like and such enclosures have included various valves for allowing a person to drink from such receptacles.
Prior art U.S. Pat. Nos. 2,578,201 and 3,739,938 are exemplary of the prior art. These patents both disclose manually operable valves in drinking receptacle covers but do not provide any means by which steam and pressure may be relieved from the interior of the container before the drinking valve is opened. Consequently, both prior art devices, as disclosed in these patents, concurrently provide for the relief of drinking liquid and steam or pressure so that the operation of these valves is dangerous, especially when hot coffee is contained in the container and the valve is opened such as to cause the hot liquid to gush out and burn the person attempting to drink therefrom.